Accuracy of implant placement in the posterior maxillary region depending on the alveolar residual bone height and sinus morphology: An in vitro study

Objectives: The primary aim of this in vitro study was to assess the effect of alveolar residual bone height in the posterior maxilla on the accuracy of the final implant position via free-handed and static Computer-Assisted Implant Placement (sCAIP). The secondary aim was to evaluate the influence of the maxillary sinus morphology on the accuracy of final implant position.Materials and Methods: Partially edentulous standardized maxillary models simulating three different residual bone heights and different sinus floor morphologies were investigated. One-hundred eighty equally distributed implants, which were placed either free-handed or sCAIP, constituted the study sample. 3D digital deviations were obtained by superimposing the post-surgical scans on the initial treatment plan.Results: Angular and linear deviation assessment demonstrated higher implant position accuracy in the sCAIP group. sCAIP revealed similar outcomes independently of the alveolar bone height and sinus floor morphology. Contrarily, in the free-handed group, alveolar bone height and sinus morphology statistically affected the final implant position. Non-parametric three-way ANOVA showed significance for implant placement protocol (p < .0001) and alveolar bone height (p & LE; .02) when angular, and linear deviations were evaluated. Sinus morphology was statistically significantly associated with angular deviation (p = .0009).Conclusions: sCAIP demonstrated higher 3D implant position accuracy. Alveolar bone height (strongly) and sinus morphology are associated with the accuracy of final implant position when the free-handed implant protocol is followed. However, these anatomical factors did not affect final implant position during sCAIP.